Abstract

Background: Countermovement jump (CMJ) ability is an important contributor to successful performance in many sports. While the drop jump, squat, jump squat and power clean training exercises are each purported to enhance maximal CMJ jump height, there are generally inconsistent findings regarding their effectiveness at doing so. The resounding implication of this is that a coach cannot be sure as to which training exercise will be most effective at enhancing their athletes’ CMJ jump height. In an attempt to address this issue a biomechanical diagnostic and
prescriptive pathway has been proposed that may allow the pre-training identification of the most effective exercise to enhance a given group’s, subgroup’s or individual’s CMJ jump height. The current study aims to test the efficacy of the proposed pathway with a single acute research study and two training studies.
Methods: All three studies required a kinetic and kinematic analysis of the CMJ and each training exercise under examination (study 1: drop jump, jump squat, squat and power clean; study 2: low amplitude drop jump; study 3: larger amplitude drop jump). From ground reaction force and motion data, kinetic, kinematic and coordination parameters were calculated at the whole body, hip, knee and ankle. Correlation analysis was used to identify CMJ performance
related factors (PRFs) while tests of statistical difference were used to identify the acute training stress experienced by CMJ PRFs.
Findings: Study one indicated that the proposed pathway may provide a means by which to identify the most effective exercise to enhance a given group’s, subgroup’s or individual’s CMJ jump height. However, these findings were based on the results (statistical relationships and differences) of an acute study, which required verification with training studies. The combined results of study two and
study three (drop jump training intervention studies) did not support the efficacy of the proposed pathway. This was due to the fact that (a) CMJ PRFs were not necessarily true CMJ performance determining factors, and (b) the acute pretraining stress experienced by a given CMJ PRF did not necessarily give an insight into its subsequent post-training change.
Conclusion: Based on findings ‘a’ and ‘b’ (above) the use of the proposed pathway to identify the most effective exercise to enhance a given group’s, subgroup’s or individual’s CMJ jump height cannot be supported.